Switch operating mechanism



Apnl 30, 1946. J. E. GILMAN, 3D

SWITCH OPERATING MECHANISM Filed Dec. 1, 1944 d n w A? O tmw fi c e v M m M 6 E h 0 J Patented Apr. 30, 1946 SWITCH OPERATING MECHANISM John E. Gilman, 3rd, Schenectady, N. Y., assignor to General Electric Company, a corporation of New York Application December 1, 1944, Serial No. 566.055 Claims. ((ll. 200 5) My invention relates to switch operating mechanism. in particular to mechanism for selectively operating twoswitches such as used in the starting of an electric motor for each direction of rotation, and has for its object a simple, reliable and inexpensive operating mechanism of this type provided with interlocking means for preventing the closure of both switches at the same time.

My invention is especially applicable to switches of the snap action type in which the movable contacts of the switch are spring biased either to the open or the closed circuit position so that a positive force is required to operate the movable contacts from one position to the other.

' In carrying out my invention in one form, I provide two levers mounted on a common pivot which are mechanically connected to the switches in such manner that when the switches are both open, the two levers are in substantially parallel relation. On the two levers are laterally extending projections between which extends an operating arm movable in one direction or the other to move one or the other of the levers for closure of its switch. For the opening of the switch I provide a latch member pivotally mounted on the operating arm and movable by a sta tionary projection into latching relation with the projection on the lever when the operating arm is moved from its intermediate position whereby the lever can be returned by the operating arm to its open circuit position. I

For a more complete understanding of my invention, reference should be had to the accompanying drawing, Fig. 1 of which is a front elevation view with the enclosure partly cut away showing two motor starting switches provided with operating mechanism embodying my invention; Fig. 2 is an enlarged view of the operating mechanism; while Fig. 3 is a sectional view taken along the line 3-3 of Fig. 1 looking in the direction of the arrows.

Referring to the drawing, I have shown my inventionin one form as applied to the operation of'two motor starting switches l and 2 for controlling the starting and stopping of an electric motor for each direction of rotation, these switches being shown as having three poles for a three-phase motor, The movable contacts of the switch are operated by means of slider members I and 4 made of electrically insulating material,

on each of which are mounted three spring pressed bridging contacts 5, 8, and I. It will be understood. that each of these bridging contactsextends in a direction perpendicular to the drawing, and each cooperates with a pair of stationary contacts spaced apart in a direction perpendicular to the drawing. The two sliders 3 and 4 are shown in Fig. 1 in their lowermost open circuit positions.

For the selective opening and closing of the switches l and 2, I provide operating mechanism comprising two levers 8 and 9 mounted at substantially their centers on a common pivot 10, as shown most clearly in Fig. 2. The lower ends of these levers, as seen in Fig. 2, are connected respectively by means of links H and 12 to crank arms I3 and I4 operating cam means for movement of the sliders 3 and 4. As shown in Fig. l, the shaft 15 of the crank arm i4 is provided with a cam projection l6 which moves in a rectangular opening ll in the slider 4 and engages the upper and lower walls of this opening to raise and lower the slider member. A similar cam operating means is provided for the slider 3, the two crank arms l3 and I4 extending in substantially opposite directions, as seen in Fig. 1, when the two switches are open. This arrangement of the crank arms provides for clockwise rotation of each crank arm for closure of its switch when the levers 8 and 9 are turned respectively counterclockwise and' clockwise from their intermediate substantially parallel positions shown in Fig. l and in Fig. 2 by respectively full and dotted lines.

For the operation of the levers 8 and 9, I provide projections 8a and Be on the upper ends of the levers extending laterally perpendicular to the drawing, as seen in Fig. 2. Between these two projections is movable an operating 'arm is mounted on the pivot Hi. When the arm I9 is moved clockwise from an upright intermediate position, it engages the projection 9a and moves the lever 9 with it whereby the lever 9, link H and crank l3 are moved from their dotted line open circuit positions to their full line closed erating arm lfl .is in its intermediate position,

embraces a stationary projection 26. On its upper end the latch member is provided with latching projections 2'! and 28 arranged to engage re spectively the projections 8a and So when the latch member is'moved about its pivot 23 by engagement with the stationary projection 26.

For example, when the arm 19 was moved clockwise from its central position to the switch closed position (shown in full lines in Fig. 2), the projection 24 on the latch member engaged the stationary projection 26 as the arm 19 was moved whereby the latch member was moved about its pivot 23 clockwise to the position shown in full lines with the latch projection 28 on the side of the projection 9a opposite the arm l9. Therefore, when the operating arm I9 is moved back counterclockwise, the projection 28 carries the lever 9 back to its open circuit position. The reverse operation of the latch member 22 to the position shown in dotted lines for movement of the lever 8 will be understood from the preceding description.

The latching projections 27 and 28 are so positioned on the latch member that the force applied to them in moving the levers 8 and 9 is in a direction passing through the axis of the pivot 23 so that the latch members are not rotated by this force. When the arm I9 approaches its central position, however, the latch member is returned to its intermediate position by the engagement of one or the other of the prong 24 and 25 with the projection 26. From the full line position of Fig. 2, the prong 25 engages the projection 26 to return the latch member. Preferably, as shown in Fig. 3, a latch spring 29 is provided on the operating arm l9 which has a projection 30 in position to move into one of the three holes 3|, 32, and 33 in the latch member in arcuate relation with the pivot 23. This spring latch serves to hold the latch member frictionally in its proper latching position after the projection 26 is disengaged a well as in its middle released position. Preferably, the operating arm I9 is turned by means of a handle 34 secured to the pivot shaft H], which also is secured to the arm l9. A suitable bearing 35 is provided for the shaft ID on the enclosing casing 36 for the switches and mechanism.

While I have shown a particular embodiment of my invention, it will be understood, of course, that I do not wish to be limited thereto since many modifications may be made and I therefore contemplate by the appended claims to cover any such modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. The combination with two switches, of two levers, mechanical connections between said levers and said switches respectively so arranged that said levers are in predetermined positions when said switches are in predetermined positions, an operating member, cooperating mechanically engaging means on said operating arm and said levers arranged so that when said op erating member is moved it engages one or the other of said levers in dependence upon its direction of movement for operation of one of said switches to its other circuit position, and latching means responsive to the movement of said operating member for engaging one or the other of said levers for return movement of'each of said levers to its said predetermined position and reverse operation of its said switch.

2. The combination with two switches, each being provided with means for biasing it in its open or closed circuit position, of two levers mounted on a common intermediate pivot, mechanical connections between two adjacent ends of said levers and said switches respectively so arranged that said levers are in substantially parallel relation when said switches are in predetermined positions, an operating member, cooperating mechanically engaging means on said operating arm and said lever arranged so that when said operating member is moved it engages one or the other of said levers in dependence upon its direction of movement for operation of one of said switches to its other circuit position, latching means on said operating member, and means responsive to the movement of said operating member for moving said latching means with relation to said operating member to engage one or the other of said levers for return movement of each of said levers and reverse operation of its said switch.

3. The combination with two switches, each being provided with means for biasing it in both its open and closed circuit positions, of two levers mounted on a common intermediate pivot, mechanical connections between tw adjacent ends of said levers and said switches respectively so arranged that said levers are in substantially parallel relation when said switches are in predetermined positions, a laterally extending projection on the other end of each of said levers, said projections being spaced apart in the direction of movement of said levers when said levers are in substantially parallel relation, an operating member extending between said projections so that when said operating member is turned it engages one or the other of said projections in dependence upon its direction of movement for operation of one of said switches to its other position, and latching means on said operating memer movable with relation to said operating member to engage one or the other of said projections for return movement of each of said levers and reverse operation of its switch, and means responsive to the movement of said operating arm for moving said latching means.

4. The combination with two switches provided with overcenter spring snap action means, of two levers, mechanical connections between said levers and said switches respectively so arranged that said levers are in substantially parallel relation when said switches are in predetermined positions, a laterally extending projection on each of said levers, an operating arm extending between said projections so that when said operating arm is turned it engages one or the other of said projections in dependence upon its direction of movement to operate one or the other of said switches to its other circuit position, a stationary projection adjacent said operating arm, a latch member pivotally mounted on said operating arm provided with a pair of prongs located on opposite sides of said projection when said operating arm is in an intermediate position whereb said latch member is turned by said projection when said operating arm is turned to operate one of said switches, and a latching projection on said latch member for engaging the projection of the lever which is moved when said latch member is moved by said stationar projection for returning said lever to its open circuit position.

5. The combination with two switches provided with overcenter spring snap action means, of two levers mounted on a common pivot, mechanical connections between said levers and said switches respectively so arranged that when said switches are both open, said levers are in parallel relation, a laterally extending projection on each of said levers;v said projections being spaced apart in the direction of movement of said levers when said levers are in parallel relation, an operating arm mounted for movement on said pivot extending between said projections in parallel relation with said levers when said switches are open so that when said operating arm is turned on its pivot, it engages one or the other of said projections in dependence upon its direction of movement to operate one or the other of said switches to its closed circuit position, a stationary projection adjacent said operating arm, a latch member pivotally mounted on said operating arm provided with a pair of prongs located on opposite sides of said projection when said arm is in said intermediate position whereby said latch member is turned by said projection when said arm is turned to operate one of said switches to its closed circuit position, and a projection on said latch member for engaging said projection of the lever which is moved when said latch member is moved by said stationary projection for returning said lever to its open circuit position.

JOHN E. GILMAN, 31m. 

